Twin clutch transmissions and processes for their control are known. In a twin clutch transmission, both partial drive trains are operated alternately by closing the respective associated friction clutch. During the operation of one partial drive train, the other one is prepared for the next operation. This means, among others, that according to a preselection strategy, the next likely gear in the driving operation is already preselected; for instance, in a twin clutch transmission with gearwheel pairs comprising a fixed gear and a selectable mating gear is already engaged, wherein the shifting clutch connecting the mating gear with the corresponding shifter shaft is already shifted or prepared for shifting. Once the gear to be activated is engaged, shifting takes place by overlapping the two friction clutches, thus by concurrent actuation of the friction clutch, from the closed into the opened state in the active partial drive train, and from open to the closed state of the friction clutch in the partial drive train to be activated anew. In the then deactivated partial drive train, a further gear is subsequently prepared for shifting or engaged immediately according to the preselection strategy.
Due to stress on friction clutches during start-up processes, in particular under heavy load, successive rapid gearshifts, thus overlapping gearshifts being constantly associated with clutch slip can impair the transmission capacity of the friction clutches; so that, under certain circumstances, the transmission capacity drops, thus the maximum clutch torque is no longer transmitted because, for instance, the friction linings of the friction clutches fade due to decreased coefficient of friction. Subsequently, the prevailing torque of the internal combustion engine in that case can no longer be transmitted and undesired slip occurs. To rectify this, the engine torque is reduced. This can jeopardize the propulsion of the vehicle equipped with the twin clutch transmission.